To a solution of triphosgene (0.08 g) in dichloromethane (7 ml) was added dropwise a solution of 1-(4-aminophenyl)-N-cyclopropyl-5-propyl-1H-1,2,3-triazole-4-carboxamide (0.21 g) obtained in Example 1d) and N,N-diisopropylethylamine (0.13 ml) in dichloromethane (3 ml) under ice-cooling, and the mixture was stirred under ice-cooling for 30 min. A solution of benzylamine (0.12 ml) and N,N-diisopropylethylamine (0.13 ml) in dichloromethane (3 ml) was added. The mixture was stirred at room temperature for 20 hr and diluted with ethyl acetate. The ethyl acetate solution was washed with water and saturated brine and dried over anhydrous magnesium sulfate. The solvent was evaporated under reduced pressure, and the residue was purified by silica gel column (hexane/ethyl acetate=1/1 to ethyl acetate). The resultant product was recrystallized from diethyl ether/methanol to give the title compound as a colorless powder (0.16 g, 52%).
